Influence of soil nutrient management on the weed control efficacy of atrazine in maize

Abstract

The improvement of soil nutrient status by appropriate fertilizer management practices may favour crops in the competition against weeds which have inherent mechanisms for effective nutrient mining from soils. Field experiments were conducted in 2011 (late season) and 2012 (early season) at the Teaching and Research Farm of Federal University of Technology, Akure, Nigeria to evaluate the influence of 350 kg ha-1 of NPK 20-10-10 fertilizer and neem seed-based fertilizer (NSBF) at various rates on the weed control efficacy of atrazine applied preemergence at the recommended rate of 3.0 kg a.i. ha-1. The results show that NPK 20-10-10 combined with atrazine provided effective weed control which did not differ significantly (P<0.05) from NSBF whose efficacy was rate dependent in both years. Maize plant growth parameters increased in response to herbicide-fertilizer combinations which reflected in higher grain yields. The NSBF increased soil pH and organic matter and ensured the supply of needed nutrients as indicated by the levels after harvest compared to the NPK fertilizer and control treatments. The presence of NSBF conferred better efficacy on atrazine for weed control and this compatibility increased the competitive edge of field-grown maize.